In experiments using graphene, researchers in Switzerland have been able to demonstrate a phenomenon predicted by a Russian physicist more than 50 years ago. The observation of the Lifshitz transition, which describes a change in topology, depended on the creation of a double-layer graphene sample of unprecedented quality.
Researchers at Argonne National Laboratory have created a small scale “hydrogen generator” that uses light and a 2-D graphene platform to boost production of the hard-to-make element. The research also unveiled a previously unknown property of graphene. The 2-D chain of carbon atoms not only gives and receives electrons, but can also transfer them into another substance.
Glenn Johnson, CEO of BlueVine Graphene Industries Inc., said many of the methodologies being utilized to produce graphene today are not easily scalable and require numerous post-processing steps to use it in functional applications. He said his company has developed a way to scale graphene production using a roll-to-roll chemical vapor deposition process.
While freestanding graphene offers promise as a replacement for silicon and other materials in microprocessors and next-generation energy devices, much remains unknown about its mechanical and thermal properties. An international team of physicists, led by a research group at the Univ. of Arkansas, has recently discovered that heating can be used to control the curvature of ripples in freestanding graphene.
Many a great idea springs from talks over a cup of coffee. But it’s rare and wonderful when a revelation comes from the cup itself. Rice Univ. theoretical physicist Boris Yakobson, acting upon sudden inspiration at a meeting last year, obtained a couple of spare coffee cups from a server and a pair of scissors and proceeded to lay out—science fair-style—an idea that could have far-reaching implications for the nanotechnology industry.
Rice Univ. scientists who created a deicing film for radar domes have now refined the technology to work as a transparent coating for glass. The new work by Rice chemist James Tour and his colleagues could keep glass surfaces from windshields to skyscrapers free of ice and fog while retaining their transparency to radio frequencies (RF).
A new method for controllably constructing precise inter-nanotube junctions and structures in carbon nanotube (CNT) arrays, Northeastern Univ. researchers say, is facile and easily scalable. It will allow them to tailor the physical properties of nanotube networks for use in applications ranging from electronic devices to CNT-reinforced composite materials found in everything from cars to sports equipment.
In recent years, it has become possible to see directly individual atoms using electron microscopy, especially in graphene. Using electron microscopy and computer simulations, an international team has recently shown how an electron beam can move silicon atoms through the graphene lattice without causing damage.
The very idea of fibers made of carbon nanotubes is neat, but Rice Univ. scientists are making them neat—literally. The single-walled carbon nanotubes in new fibers created at Rice line up like a fistful of uncooked spaghetti through a process designed by chemist Angel Martí and his colleagues.
When moving through a conductive material in an electric field, electrons tend to follow the path of least resistance—which runs in the direction of that field. But now physicists have found an unexpectedly different behavior under very specialized conditions—one that might lead to new types of transistors and electronic circuits that could prove highly energy efficient.
Scientists have married two unconventional forms of carbon to make a molecule that conducts electricity in only one direction. This tiny electronic component, known as a rectifier, could play a key role in shrinking chip components down to the size of molecules to enable faster, more powerful devices.
Typically a highly conductive material, graphene becomes a semiconductor when prepared as an ultra-narrow ribbon. Recent research has now developed a new method to selectively dope graphene molecules with nitrogen atoms. By seamlessly stringing together doped and undoped graphene pieces, ”heterojunctions” are formed in the nanoribbons, allowing electric current to flow in only one direction when voltage is applied.
New research at the Univ. of Maryland could lead to a generation of light detectors that can see below the surface of bodies, walls and other objects. Using the special properties of graphene, a prototype detector is able to see an extraordinarily broad band of wavelengths. Included in this range are terahertz waves, which are invisible to the human eye.
On the macroscale, adding fluorine atoms to carbon-based materials makes for water-repellant, non-stick surfaces, such as Teflon. However, on the nanoscale, adding fluorine to graphene vastly increased the friction experienced when sliding against the material. Through a combination of physical experiments and atomistic simulations, a Univ. of Pennsylvania research team has discovered the mechanism behind this surprising finding.
A flexible display incorporating graphene in its pixels’ electronics has been successfully demonstrated by the Cambridge Graphene Centre and Plastic Logic. The new prototype is an active matrix electrophoretic display, similar to the screens used in today’s e-readers, except it is made of flexible plastic instead of glass. This advance marks the first time graphene has been used in a transistor-based flexible device.
Nearly 20 years ago researcher Alex Zettl of the Lawrence Berkeley National Laboratory synthesized in his laboratory a new material never before seen by nature: boron nitride nanotubes, the strongest, lightest, most thermally conducting and most chemically resistant fiber known to exist. Now a startup has licensed this technology with the aim of manufacturing boron nitride nanotubes for commercial use.
A new atomically thin 2-D ultrasensitive semiconductor material developed by researchers California promises to push the boundaries of biosensing technology toward single-molecule detection. Based on molybdenum disulfide or molybdenite, the biosensor material which is used commonly as a dry lubricant, surpasses graphene’s already high sensitivity, offers better scalability and lends itself to high-volume manufacturing.
Lighter, more flexible and cheaper than conventional solar-cell materials, carbon nanotubes (CNTs) have long shown promise for photovoltaics. But research stalled when CNTs proved to be inefficient, converting far less sunlight into power than other methods. Now a research team has created a new type of CNT solar cell that is twice as efficient as its predecessors.
Scientists in The Netherlands have demonstrated that they can detect extremely small changes in position and forces on very small drums of graphene. Graphene drums have great potential to be used as sensors in devices such as mobile phones. Using their unique mechanical properties, these drums could also act as memory chips in a quantum computer.
A new argument has just been added to the growing case for graphene being bumped off its pedestal as the next big thing in the high-tech world by the 2-D semiconductors known as MX2 materials. An international collaboration of researchers led by Lawrence Berkeley National Laboratory has reported the first experimental observation of ultrafast charge transfer in photo-excited MX2 materials.
Research published in ACS Nano identifies a new type of sensor that could monitor body movement and advance the future of global health care. Although body motion sensors already exist in different forms, they have not been widely used due to their complexity and cost of production.
Graphene may be tough, but those who handle it had better be tender. The environment surrounding the atom-thick carbon material can influence its electronic performance, according to researchers at Rice and Osaka universities who have come up with a simple way to spot contaminants.
Researchers in Europe have succeeded for the first time in growing single-walled carbon nanotubes with only a single, prespecified structure. The nanotubes thereby have identical electronic properties. The decisive trick was producing the carbon nanotube from custom-made organic precursor molecules.
As hemp makes a comeback in the U.S. after a decades-long ban on its cultivation, scientists are reporting that fibers from the plant can pack as much energy and power as graphene, long-touted as the model material for supercapacitors. A team has figured out how to make electrodes from certain hemp fibers, and the breakthrough came from figuring out how to process them.
Researchers at the National Physical Laboratory in the U.K. have discovered that the conductivity at the edges of graphene devices is different to the central material. The group used local scanning electrical techniques to examine the local nanoscale electronic properties of epitaxial graphene, in particular the differences between the edges and central parts of graphene Hall bar devices.
Some of the most damaging brain diseases can be traced to irregular blood delivery in the brain. Now, Stanford Univ. chemists have employed lasers and carbon nanotubes to capture an unprecedented look at blood flowing through a living brain. The technique was developed for mice but could one day be applied to humans, potentially providing vital information in the study of stroke and migraines.
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